44 



It is with some hesitation I refer this and the following 

 species to the above genus, not having seen the hinge nor 

 the pallial impression ; and the muscular impressions are 

 very obscure. There is however, on the cast a distinct de- 

 pression extending from the posterior side of the beaks ob- 

 liquely downwards and backwards, near the cardinal edge 

 of each valve, as though produced by an internal thicken- 

 ing of that part of the shell, as in the genus Thracia. It 

 may be a Periploma or a Tellina. 



Thracia ? subtruncata. — Shell elliptical-ovate, thin, much 

 compressed, rather narrowly rounded before, and vertically 

 subtruncate posteriorly ; right valve a little more convex 

 than the left ; base forming a broad elliptic curve ; cardinal 

 border sloping with a gentle curve in front of the beaks, 

 nearly straight and horizontal behind them ; beaks almost 

 central, small, not much elevated, and in close contact. 

 Surface (of worn specimens) retaining near the border a 

 few small indistinct concentric wrinkles, and faint lines of 

 growth. Immediately behind the beaks, the cast shows on 

 each valve a distinct depression passing obliquely backwards 

 and downwards. Below this depression, an undefined ridge 

 passes from near the beaks towards the lower posterior 

 border. 



Length 1°84 inches; height 1*14 inches; breadth *51inch. 



As I have had no opportunity of seeing the hinge or any 

 of the internal characters of this shell, it is only provision- 

 ally I refer it to the above genus. Better specimens may 

 prove it to be a Tellina or a Periploma. From the species 

 last described, it differs in being proportionally less elon- 

 gated, and the cardinal edge is straighter and more nearly 

 horizontal behind the beaks. The anal end is also broader 

 and differs in being rather distinctly truncated. 



Dentalium Nanaimoensis. — Shell slightly arcuate, and 

 rather rapidly tapering ; section circular ; surface orna- 



